REUTERS/Ruben SprichU.S. Secretary of State John Kerry (L) and Russian Foreign Minister Sergei Lavrov shake hands after making statements following meetings regarding Syria, at a news conference in Geneva September 14, 2013.

MOSCOW (Reuters) - Russian Foreign Minister Sergei Lavrov told U.S. Secretary of State John Kerry on Sunday opponents of Ukraine's Viktor Yanukovich had failed to abide by a peace deal they signed on Friday and had seized power, the ministry said.

In their second telephone conversation in two days, Lavrov told Kerry "the most important thing now is to provide for the complete fulfillment" of the agreement brokered by three top European Union diplomats, the Russian Foreign Ministry said.

"The Ukrainian opposition is deviating from the agreement, having in effect seized power in Kiev, refused to disarm and continued to place its bets on violence," Lavrov told Kerry, according to a ministry statement.

Lavrov "drew attention to the fact that the document bears the signatures of representatives of several Western states, and that the United States officially welcomed its conclusion," it said.

A Russian envoy sent by President Vladimir Putin to participate in mediation efforts did not sign the peace deal. Since its signing, Yanukovich has fled the capital and lawmakers have voted to oust him and name a temporary replacement.

The dramatic events followed a deadly two-month standoff that began when Yanukovich shelved plans to sign political and trade deals with the EU and said Ukraine would seek closer ties with Moscow, which swiftly offered a $15 billion bailout.